/tmp/test_that_results_dtsLyX/results-01-network_WiFi_BluetoothStreamPerf.11a                                      [  FAILED  ]
/tmp/test_that_results_dtsLyX/results-01-network_WiFi_BluetoothStreamPerf.11a                                        ERROR: sox command is not installed. sudo emerge sox to install sox in chroot
/tmp/test_that_results_dtsLyX/results-01-network_WiFi_BluetoothStreamPerf.11a/network_WiFi_BluetoothStreamPerf.11a [  FAILED  ]
/tmp/test_that_results_dtsLyX/results-01-network_WiFi_BluetoothStreamPerf.11a/network_WiFi_BluetoothStreamPerf.11a   ERROR: sox command is not installed. sudo emerge sox to install sox in chroot
/tmp/test_that_results_dtsLyX/results-02-network_WiFi_BluetoothStreamPerf.11b                                      [  FAILED  ]
/tmp/test_that_results_dtsLyX/results-02-network_WiFi_BluetoothStreamPerf.11b                                        ERROR: sox command is not installed. sudo emerge sox to install sox in chroot
/tmp/test_that_results_dtsLyX/results-02-network_WiFi_BluetoothStreamPerf.11b/network_WiFi_BluetoothStreamPerf.11b [  FAILED  ]
/tmp/test_that_results_dtsLyX/results-02-network_WiFi_BluetoothStreamPerf.11b/network_WiFi_BluetoothStreamPerf.11b   ERROR: sox command is not installed. sudo emerge sox to install sox in chroot

I'm guessing sox just needs to be added as a dependency to some BT test?